1. Field of the Invention
The present invention relates to a switching control circuit for use in a radio communication apparatus. In particular, the present invention relates to a switching control circuit for use in a radio communication apparatus for transmitting and receiving a signal with switching over between a GSM (Global System for Mobile Communication) mode and a CDMA (Code Division Multiple Access) mode, and a radio communication apparatus including the switching control circuit, where the GSM mode is a mode such as a GSM system, and the CDMA mode is a mode such as a WCDMA (Wideband Code Division Multiple Access) system or a CDMA 2000 system.
2. Description of the Related Art
In recent years, a mobile telephone has been developed and put to practical use, where the mobile telephone has a multi-mode radio communication function for selectively switching over between the GSM mode, such as the GSM system which is called the second generation, and the CDMA mode which is called the third generation.
Nowadays, in the GSM system, a mobile telephone system has been established by using a quad-band that uses four bands in total including two bands located in 800 MHz band and two bands located in 1.8 GHz band. In addition, in the WCDMA system, a mobile telephone system has been established by using nine bands of Bands I to IX.
In order to constitute a multi-mode transmitter circuit for switching over among a plurality of different systems as described, a multi-mode radio apparatus according to a prior art was constituted by including a switching controller circuit for selectively switching over among the plurality of systems and bands, and a controller for controlling the operation of the switching controller circuit (See United States patent application publication No. 2004/0166823, and semiconductor product information “NJG1540JA3, 5×10 dual-band antenna switch GaAsMMIC”, New Japan Radio Co., Ltd., http://semicon.njr.cojp/pdf/ie/ie10008.pdf, Apr. 3, 2006).
However, the radio communication apparatus constituted as stated above and having the GSM mode and the CDMA mode has such a problem that as the number of modes and bands switched over by the controller increases, the number of control signals for controlling the switching control circuit increases, and the number of signal lines between the controller and the switching control circuit increases. Accordingly, as the number of devices such as antennas, demodulators, and modulators increases, which are switched over with the switchover among the modes and the bands, the number of signal lines between the switching control circuits provided in the respective devices and the controller increases. This leads to such a problem that the circuit size of the entire radio communication apparatus becomes larger.